The present invention relates to a solution for defining the rights of access to the operating system of a telephone switching system.
In almost all multiple-access data networks, some kind of user identification method is used. Such data networks include e.g. internal networks within enterprises as well as networks used in schools and universities. Access right verification of various degrees is also often applied in conjunction with industrial equipment and control of such equipment or associated software updates. This type of systems include the operating system of a telephone switching system. Here, the operator has defined a number of users who have the right to control the operation of a switching center via its operating system.
The commonest method for user identification is to give the user a personal user identifier and a password associated with it. The password is generally not known to the maintainer of the network. If the password is stored in an encrypted form, it cannot be deciphered afterwards. The user identifier and password are typically associated with a validity period defined separately for each user identifier. At the change of the day, the validity data for each user identifier is decreased by one. When the validity period of the user identifier is reduced to zero, the user identifier becomes invalid.
A problem with the above-mentioned solution is that the validity period of user identifiers is in most cases defined in terms of complete days of use starting from the current instant and that the validity of the user identifier is not dependent on any other condition or parameter.
The object of the present invention is to eliminate the above-mentioned drawbacks or at least to significantly alleviate them.
A specific object of the invention is to disclose a new type of method and system which allow the validity period of user identifiers and/or user profiles and/or passwords in the operating system of a telephone switching system to be defined as a number of log-on times, as active session time and/or as a function of commands used.
As for the features characteristic of the present invention, reference is made to the claims.
The method of the invention concerns the definition of access rights in a telephone switching system comprising functions for controlling the operating system of the telephone switching system on the basis of commands entered.
According to the invention, the right of access to the operating system is defined by means of a user identifier and an associated password. By entering his user identifier and a valid password associated with it, the user can log on into the operating system of the telephone switching system. One or more user identifiers may be grouped under the same profile. In this context, the concept of xe2x80x98profilexe2x80x99 means that all those covered by the same profile have uniform rights and user identifier validity periods and are subject to the same conditions regarding expiry of identifiers.
In the method of the invention, it is possible to define a weighting value for an operating system command. The weighting value is e.g. a number whose magnitude reflects the importance or xe2x80x9cpowerxe2x80x9d of the command used. Furthermore, the validity parameter associated with the user data is decreased on the basis of the weighting values of commands entered. In this context, xe2x80x98user dataxe2x80x99 means e.g. user identifier, user profile or password. When the validity parameter associated wit the user data has been defined as a function of time, the time parameter associated with the identifier is decreased in accordance with the number of times of use. The amount of time by which the parameter is reduced is preferably the amount of time spent on each session or the elapsing time in general. A further criterion of decreasing the parameter may be the number of log-on times. Each time when the user logs on into the system, the validity parameter associated with the user data is decremented by one.
The weighting values of commands entered may also be used as a parameter for reducing the validity period associated with the user data. This is based on the idea that each command has a characteristic weighting value by which the validity parameter is decreased when the command is issued. A given weighting value corresponds e.g. to a predetermined amount of time. The validity parameter is not necessarily bound to time. Therefore, each user has an individual starting level of the validity parameter, which is reduced in accordance with the commands issued. As an example, let it be stated that a delete command probably has a higher weighting value than a print command. If the commands employed by the user mainly consist of commands having a higher weighting value, then, measured as a length of time, the validity period of the user data is shorter than in the case of lower weighting values. If the user tries to execute a command whose weighting value exceeds the value of the validity parameter, then the command will not be executed.
In the telephone switching system, it is possible to dynamically change the validity periods associated with user identifiers and/or user profiles. In this case, the validity period can be changed even if the user identifier and the associated password are still valid at the instant in question. Correspondingly, it is possible to define user identifiers and/or user profiles with an unlimited validity period.
When the validity period of the user identifier and/or user profile expires, the user identifier has no access right any longer. If the validity period of the user identifier expires while the user is having a session active, then the session is terminated and the user is notified about the identifier being outdated. Further, the telephone switching system may have a property whereby the user is given notice of future expiry of the password associated with the user identifier a predetermined length of time before the user identifier expires. For instance, the user may get a message saying that the user is entitled to five more times of log-on into the telephone switching system. If the password is already outdated when user logs on into the system next, then he will not have a right to use any other system commands except the command for changing the password.
The system of the present invention comprises means for defining a weighting value for an operating system command and means for decreasing a validity parameter associated with user data on the basis of the weighting values of commands issued. Furthermore, the system comprises means for canceling the access rights of a user identifier when the validity period of the user identifier expires, and means for changing the validity period of a user identifier and/or user profile while the user identifier and/or the user profile are/is still valid.
In a preferred embodiment of the invention, the system comprises means for terminating the session and notifying the user if the validity of the user identifier expires during an ongoing session, means for notifying the user about future expiry of validity of the user identifier in advance by a given length of time before the user identifier becomes outdated and means for defining user identifiers and/or user profiles with unlimited validity. In addition, the system comprises means for allowing log-on of the user into the telephone switching system and preventing the use of other commands except a password change command if the user""s password has become outdated.
The present invention allows easier management of rights of access to a telephone switching system. Furthermore, the invention makes it possible to define user identifiers and/or user profiles with accurate validity attributes. At the same time, the security of the telephone switching system can be improved.